We propose to investigate in-vivo cell membrane structure of gram-positive (B. subtilis) and gram-negative (S. oneidensis) bacteria adhered to a silicon oxide surface using neutron reflectometry. This will allow us to test whether NR can be employed to qualitatively examine the cell membrane structure of live organisms. If successful this work help to define an experimental protocol to characterize in vivo cell membrane allowing for a new branch of science to be conducted using the highly penetrating but none destructive nature of neutrons. If this trail work is successful future experiments will intend to examine the difference in membrane structure between mesophilic and pressure adapted bacterial strains. Allowing us to better understand the mechanism of pressure adaptation, providing an insight into how these cells can protect the structural integrity of their cellular components.